SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60337f2b98e8d3903841e112b64dfc63d7a729bc52825bab1990052ae302f18a' 
  AND token = 'j9bYWoPxRCmQV55Hfdx5ckiMhFkYGDk5b6SO6cCY50U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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