SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0eb1837c459c87fda7ec21ff924ac85691a6f09aff059af040d1cc5abf11c8' 
  AND token = 'Vi59uS1ywlEKFoP4EyRkt3G4FwEsTKDxP9G2QDki49o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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