SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '592483feb77619dfa9f3ab15fcf40b785f7c235ee7eec3126909f33aa7260117' 
  AND token = 'rS56Y8NOlJpwGZkY+gnmnVkkzkccdBjEbxq9JAhFaKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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