SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf3745ad467911cfb74a7d2d902b1e992a5ac92757836c3750128ee49dde9b9c' 
  AND token = 'VjWP7kug018mSdi+axPsww1PG5PO4zsZCvzbbHN6PwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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