SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f986b9d30c9099e2bdd58a2c3042514f8286f4ed5da0004ea541acecd5dd343d' 
  AND token = 'QIfhgFKfaq7Sf+vZxFXJy2xDkgi/Vv3vJouJvRhBfgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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