SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a8c467d027cd9f7addedcd757caf086cf3d6e1942a45af3f0b40b33b7c1b12d' 
  AND token = 'OQjimE/7bgHluHpAGG8nir/bAGv6f/Swr6uIrSOpKVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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