SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b00b2e6a6b0ec35ac3509daec30d6d51a445f5721cdd269ba1ff5d70a02022d' 
  AND token = '3NHdQXUd6/Q74pH8a8gW+HvIZWnyD8z+KNSTvG7CnlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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