SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5a4ffd7705a473febc4e8e98a67624e83d0165ba334825d256ac34874df7a74' 
  AND token = '8hk2Rbk3infYw6uJybWZurwahLjVVfOvukFY5EMZoro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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