SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0da089ecb07380fd13958a8629f71644d83e467a39dd16b429dfdec789afc3a7' 
  AND token = '95OBpkH4wVRm/L2qjveZnc7tNZ2/yzorkImKAklHp68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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