SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87826de0f17979201524c42d2b0d56549f45a2ddfc2a78873cfdc3ebe6529a62' 
  AND token = 'TWbHAeTSbDlZ6veGPfJCjg7ayRp6PrmaI4cYrmaA7z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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