SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6542f6248094315815cb369862e4dcf6fa7d53308cd4233d28f3e80290a799cf' 
  AND token = 'edpL3nf/trtWUeN1pwUoOnimyj5CAJAGcfjT8uyuByU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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