SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b52284fb233a7b67bcbf8cc346144aa77c929c770eea574cb015eba00c160632' 
  AND token = 'sFoV8vHOKid2T6MSRDObtvvVw+LNm51ZDnQ4JgYKwSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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