SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcbaa964b70e7e809fdd20eff84fafbb026d741035d4f066c14c2879b7a31f8c' 
  AND token = 'x3aXPWURQXQy1WfkVHdvdiIAQoo7SZ9ofROtYIjSVJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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