SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1711abbc71d9ec9e3f438f5b70250b540df1b81983785dfb6f8621a3019b034' 
  AND token = '7WiFke/3NHPJAyxxvKVRdoeID/ZWJ/uT1v5jGzmkcm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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