SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39cdfcb99c1280992dac64755b25ee4940f190c68d71fc2e60396101b44e0a84' 
  AND token = 'imUFQlG+FiFP1XcZFhtqeBLx/okIrHp1JL4PqUgzgJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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