SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fce4931be3563dd88f20f0948d90a7ea323872ef68981e1c9e96a3de5482b32' 
  AND token = 'vtlnYtvc6ulh7vehL90TU10Bk9JXfJn4xKPDXdJIoMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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