SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec1e4bd4201303f8a20e4b05711ba7b55d16a272172b6c5a682388185281afe7' 
  AND token = 'W9Ueei8z4wYyGhzpNlRTZFkg+4Sw8E1SCSUVBnVonPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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