SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17297ddcba3dfa8a66293a941420fd835cac365576cca5784f13144489c9dfe9' 
  AND token = '1vVpQiSANkJi2FTlMikTLHBNYbN1gX8gCGoqHuWqG5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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