SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f60d60cf6e168076f8cedd522a89ac0e12580add3ea1b78fc833160640217ad4' 
  AND token = 'lXntJd+VPUYY2QcMNi3ZLWleWvcnHG/kerMgB5IDT5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}