SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41295c14a02fe472bd4e219deaee56297195ed96aedf5de1f4188dfd82638555' 
  AND token = 'oMv+b86HgwUp/4rlgAF+U3bcFdZYwEv3HVEgTMkIJTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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