SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53bb8ff4e18fdaa79a07dd1bad9eb510d1f1a9cc43b38941136759583a56dc3a' 
  AND token = 'scadCXNyLnXv3aLFjgWMedMhu8JEMxIdRuOqGaUI8C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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