SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a24c93ed553264b460834ba3cfc3a2720ca61459cbd3ec845810d081cdc47953' 
  AND token = 'ot0478yy71RpTWaR1NCpJY3eO3VCGouc7hiBDq6nP1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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