SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e68fc0780f6f307cea72ebacaa2dababedee2abf2bc77a0c39ec4c211c6bdf2c' 
  AND token = 'USIFHiAirwD1VNz8SCOgvAcThZ8ZObBGkaS/IaxNqdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}