SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66fafbd1d6c8406d7eca67000681c33298ffc2dbe59a444420270a41e0686de0' 
  AND token = 'TGHfXDgFCXTt0IzxTha/8uNDRspWDunsF4yJNHUxoHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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