SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cacf4c771f3bf49cff800722e97f9d14c3cc55201b68ce6b651bc13eb2fb259' 
  AND token = 'qKm9ulYGbPoCfhwm5pfwYNozKzdewYEJCwVaN9FrmF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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