SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '54dadb7ea8740cadff4958a7fda9c0d1be92d2da3c7e2389f0e20875cc5d03b6' 
  AND token = 'cVGLoJePQHiRuumP8b19K1CKRCov1V1xxHFvvvWMUwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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