SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3a2f5eab6f6ec491a8257ae5db28f4dcbb269ee29a17ed721e09a821169998a' 
  AND token = '6kQ2R210HvVrv0y7+Cz6O7NRGeIdMtmXHN6QaKIc8AA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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