SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4b6b17ffa937d2255bcd15e70ec032aad5d83ae351c5d65365c85a8dcb02e7e' 
  AND token = 'r23QfW7T2+QBllGNifPk37OcaOxEULKPJpmPZUv3bXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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