SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f95a430bc8410f7670c3571bf06857399da40f7c2cfabc522e95560e236c46' 
  AND token = 'x+ggN5DP3wKe+ngCvgomaKULBvRBuvD2ZeSiBF1MGJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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