SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d04f93dc2d063d356abb6d499d5986121de314e69fa4a3761c5f00c672276a5' 
  AND token = 'N2ISf2/cStLogMSrig5J+8ILgOtTl2UsxvYWyVJuqHE=' 
  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"
    }
  }
}