SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9166f35c849139d831e81e1a659687dae4cd6b0c3623d0e6592a0d1dccee11e' 
  AND token = 'TqphHzYi7CrJNUQ+ajNxbwDZ24Wj9BgHLk4/ZJuMgGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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