SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3772ffa7471515ea0ee60c0dbf67589c6632bbb6ccf1f4331771204aeff4742' 
  AND token = 's/wgJrLlgGYzalFpvO2T4HvSqZjbypAwBIybduuYdZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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