SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '059f652f8e345ac3ee1b7331a21e53fe4f930fd678b045e65203f574c2b30c3b' 
  AND token = '4Kp0jBPug/J5nHKFqpTJkvMyDTGi52z4ZWf+BHe1s7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}