SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83551591bfc6dac2228d3cd9d645b2f39eab4e4fff99a27b3202ade580306488' 
  AND token = 'iow52A2DZpprHCsCSsVmB1rVR0YcbSVEb/8pI/qqhNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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