SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '699c4e31e88755fd9f876827bdf39cab6fba39ecc542f141d0cce7ddc9bcdd85' 
  AND token = 'gj4569PlzW2udlfbaN2SmBO7DhWQy2bqv0NCQPbcZQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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