SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b98fd79a06a7f2493a7ccef19363b7fef8b0b02b81ac29f91084a1dafc79201c' 
  AND token = 'In489LKOpgEsFjVJtCaKFo+ghRU4eNG/xcwt7m2TPo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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