SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ad50b48c342be76293a199a176c2acaca134314051e85fc835656e05210686b' 
  AND token = 'lHHMuxUFaGTPDbIJ4v3rX4WwC0jS4aEdBJU6EU2ZTh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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