SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '347fd61c8e7ecf6dde73e7f30776d119a354c102905e620956763624fcab5f5b' 
  AND token = 'B0NOvEJjSmiCnsYd8CE/fi+GPimIQaJoOVhwqBQgp6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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