SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33c994900b68f99b0142929ededbf9d6fe56ee018db1802a20ae32a1579f1dbb' 
  AND token = 'Z35G9KRxtAC4HQb0wJ2yDAkJMlArzoFWoc2cFyxMvzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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