SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e8961476642fe36a2c0789c5f5d1d2288354776838436834e664c2412c92bd' 
  AND token = 'ZA8d3GBCuBMxOWE4Zj8kzRQwXPJjIqA7A9uLTwHdS4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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