SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1e1de39b1857c99ace8bac109bc04658a02998846e13045d47868ba0e64d6a2' 
  AND token = 'fPqpatI6dbXoSrTAFsOvw1CHURi3qKjDIrTeo6z6U5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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