SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f41b2fdfb9da3b5dec801ece49f19e5cd31100c6e141e3f5e3a95fcfc398690c' 
  AND token = 'mEZxPtJ+ccsWhjgm8E8jjAXR1fQknRmZPS2LMPeoGtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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