SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef888f918c6190f065734639c8a97cb987bf64be8b785ac9b5fcf7c07b2cf0e8' 
  AND token = 'zjwnyuuTa4XtkrLuppcIpyMMKl7lqUZ+YGBzJrYv+ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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