SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eafbf978db1b8310619f66813897817604588809898a9ac10c0e2ef6fa8d6d92' 
  AND token = 'ao0oAcdnt1oc47BeoeBrmSA4MpZgOOmrPj28vegy+b0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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