SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a292aeb7e4c50a24923bef070244088c092ecde54b16c98c2572d8b6420478a3' 
  AND token = 'KCDJIhk5JG8Z6WofpTGIDTdwjGo/qFp5jw+Agqo6WgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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