SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c11fb12f63095f3b457994a4ecc3b778df02e0b5dad09113fca7d76983bc53b' 
  AND token = 'wwcwKtRpYjP2bjz+aqNBlkdUaGOr1HO3lxFx5ohKOp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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