SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddf6e040cf3ffbf10abb9ac57d2c0d631645626ed17b01da5f44c588084b3fdf' 
  AND token = 'bn3e+syx+Ep/jEkqnowYQ9yaTdclmfGeIDYtXniao8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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