SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27c73831d51fce61505d2b53f0cdcae917b204689a4c3db0b68f58cc4b2e523a' 
  AND token = 'SKz6nPYhvHwdOKou7xhzHiF90QjPCx843Q3EumhlzZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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