SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6c8256232e37455857b9ece7aa5433ee70ae2bc75fc066240c711e89bac137' 
  AND token = 'TsTFqmO0g6YRx6OEzIFlRc9J2OiWfjpYRB41thbosQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}