SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18ee98b5eafa5aad60d44614c448af33119c31bc849cdd384bab37486be06f8c' 
  AND token = 'LpExUU1skh9DhgqRaI7oMsMCBDtR4270MR+pNzUcmR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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