SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bc88b07eb92bdc2fcb5708ccc2db5dc2cbd2fa09a14438283b40c6b9d167086' 
  AND token = '5lqpf+iLsBEQ7ETyazUC/eygHA2ab8SDbfbDBkuXxCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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