SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e4c93453528b29da26e93f44787e2d515353ee976a58ce99e7a83f058ad2c0a' 
  AND token = 'W4WRXXrn8HgoDGH/wLQ1xokIeL2juZzJ7YbV1ZDSLlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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