SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '996d9e86ac08e2277d3d7cfdd8e723af8f5407857c1d203817152b1c08bd1429' 
  AND token = 'zVURBepmCJ903TDlct8ipb4Zz3aLiZ5SdUrsiiYNqME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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