SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '344c8f5c8d53d62acd00a792b2aadca7f39c19350712cc52b749eba17f800d22' 
  AND token = 'FSEzGdsgy2OCQ8FgQaBNTyTBoFWVuf2rD6ZIVCOd8D8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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