SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f211175737316029da9663d230873b2b5ab2f51a52406643f6c71e026a2e5ba3' 
  AND token = 'woJsQdlTzstSLy395yy+e84khCil3clHv4/vj/Xn2Ds=' 
  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"
    }
  }
}