SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc36e00de6ba4944901092f5fecd228174b3549a3a71cffe124d3f7f8b2a9b0f' 
  AND token = '/uk6KmXP2eLjG5mAnG+wRRG+u3WQGyFisCqvGtOwRPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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