SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f8b37857e247ed0a7f030b6b38ba7291a87ed0bd31504490d1be8b60d5f905b' 
  AND token = '37VV/UUxLm5ulLjpmqJhsCQv3cviTErMeAtHWTSXnE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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