SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f401fff1657443b6f60da71d3a8f86f7b43728141fe22b94aa49ecc545df8172' 
  AND token = 'lgTqYVsEQlyVNyrwbsxxk/LTnXRJ0GL5h4W+40OK77Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}