SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ace65328731360b95b2f3a986a81768d55107e43cdf919c18435b88ca2e0263e' 
  AND token = 'gctoXRM0oQjDHVlAllDGnFIwGSxC3nfBixkuoFG4VqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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