SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6f0f0b6df234833364bbe81c064a3a76be05754e49c937f5e2d963ea9956d5e' 
  AND token = '/ZdRDaD0dn7qTLJe8Pg31weDLdpNlisucyzqKRVZdhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}