SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b734655fce90e2dc5f3d311832344bb79c211398cb2c239b6f68e4632f13195' 
  AND token = 'K22hlLbMAFukhpdxluDoDIpoTaDp1C9c04Mlv9o4pl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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