SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c77107508b40c3de4f2139458eed484c31e3ddb8c06bb630bedb74722817e82d' 
  AND token = 'nqFrCUeH0axU1wNy/cl7jqj+XfkXyBEG5PyC2NCaT4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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